I have asked this question several times, so far without a reasonable answer. The new Super VGSs will have a lot more equipment and the expectation is that twice the equipment will produce twice the flying. The one thing that gets forgotten is that you still only have one airfield.
The call of “All clear above and behind?” is there to stop a conflict with one glider landing as another is being launched and when it isn’t clear there is a delay. This delay provokes another delay, maybe of the launch of a second glider and certainly to the landing of the first (the whole flight is delayed). This in turn starts to delay the whole operation and all the extra equipment (beyond a certain point) will do is give you a longer queue of gliders with cadets sat in them waiting for a launch.
Operating both left and right hand circuits will help and nearly double the equipment actually being used, but there is still a limit. If you have ten gliders all doing ten minute flights with ten minutes on the ground between launches (if it is more than this you are wasting resources), that means a movement (take off or landing) every minute. This makes no allowance for towing the cables out (no launches for probably ten minutes), or the break in the smooth operation for practice (or real) cable breaks, or the slowing down in the operation for a first solo. In other words, just adding more gliders and winches will not produce a comparable increase in flying.
Now, I am not saying you can’t have a very high launch rate for a while if you have lots of gliders, but pretty soon those landing start to slow things down. In a gliding competition it is possible to launch the entire 60 gliders in 30 minutes, but the only landings are being done by a small number of very experienced tug pilots who are happy to land alongside each other.
The airfield will be the limitation.